Method and apparatus for key distribution using near-field communication

Abstract

An apparatus and method to provision and distribute a traffic key amongst a plurality of radios enables secure communication, for a predetermined group or a predetermined event. Each radio has a controller, a radio transceiver for electromagnetic radio communications, and a near-field transceiver for near-field communications (NFC). The traffic key (or traffic keys) is provisioned locally at one radio and distributed to the remaining radios utilizing the NFC over a non propagating link. The same traffic key is distributed amongst all radios, and additional restrictions may be applied if desired. The same radios can later be re-provisioned for a different group or event. The local provisioning and distribution is highly advantageous for markets that do not require permanent assignment of radios.

I claim: 
     
       1. A wireless portable radio for secure group wireless communications and including an on-the-spot key provisioning function, the wireless portable radio comprising:
 a long-range radio transceiver for long-range electromagnetic radio communications; 
 a near-field transceiver for near-field communications using non-propagating signals; and 
 a controller configured to:
 one of create a traffic encryption key and select a traffic encryption key from a plurality of pre-loaded traffic encryption keys as a function of a user input, for encrypting group communications with a plurality of other wireless portable radios; and 
 in response to a user request to provision the traffic encryption key, sequentially for each of the plurality of other wireless portable radios:
 transmit, via the near-field transceiver, a traffic encryption key distribution request to the other wireless portable radio; 
 receive, via the near-field transceiver and in response to the request, an acknowledgement to the request from the other wireless portable radio; and 
 responsive to receiving the acknowledgment, transmit, via the near-field transceiver, the traffic encryption key to the other wireless portable radio. 
 
 
 
     
     
       2. The wireless portable radio of  claim 1 , wherein the traffic encryption keys are distributed to the other wireless portable radios for a duration of an event. 
     
     
       3. The wireless portable radio of  claim 1 , wherein the plurality of other wireless portable radios are rental radios that are re-provisioned with new traffic keys for each new rental customer. 
     
     
       4. The wireless portable radio of  claim 1 , wherein the near-field transceiver establishes a near-field link to the other wireless portable radios via the non-propagating signals. 
     
     
       5. The wireless portable radio of  claim 1 , wherein the wireless portable radio provisions the traffic encryption keys to the other wireless portable radios without any use of Bluetooth pairing. 
     
     
       6. A method of securing group wireless communications by on-the-spot distribution of traffic encryption keys amongst a plurality of wireless portable radios, the method comprising:
 enabling, by a first wireless portable radio, a first near-field transceiver of a first wireless portable radio for near-field communications using non-propagating signals, the first wireless portable radio comprising a long-range transceiver for long-range communication; 
 enabling, by a plurality of secondary wireless portable radios, second near-field transceivers of the second wireless portable radios; 
 at the first wireless portable radio, one of creating a traffic encryption key and selecting a traffic encryption key from a plurality of pre-loaded traffic encryption keys as a function of a user input, for encrypting group communications with the plurality of second wireless portable radios; and 
 entering, at the first wireless portable radio and in response to a user request to provision the traffic encryption key, a key provisioning mode and, sequentially for each of the plurality of second wireless portable radios:
 transmitting, by the first wireless portable radio via the first near-field transceiver a traffic encryption key distribution request to the second radio via a near-field communication link with the second near-field transceiver of the second wireless portable radio; 
 receiving, by the first wireless portable radio via the first near-field transceiver, an acknowledgement to the request transmitted via the second near-field transceiver of the second wireless portable radio; and 
 in response to receiving the acknowledgement, transmit, by the first wireless portable radio via the first near-field transceiver, the traffic encryption keys to the second near-field transceiver of the second wireless portable radio. 
 
 
     
     
       7. The method of  claim 6 , wherein the further distribution of the traffic encryption key from the second wireless portable radios is restricted. 
     
     
       8. The method of  claim 6 , wherein the plurality of second wireless portable radios are rental radios that are programmed and re-programmed for different events. 
     
     
       9. The method of  claim 6 , wherein the plurality of second wireless portable radios are rental radios, and the further distribution of traffic encryption keys is restricted. 
     
     
       10. The wireless portable radio of  claim 1 , wherein the non-propagating signals are defined as signals having a substantially magnetic field component or a substantially electrical field component but not both. 
     
     
       11. The wireless portable radio of  claim 1 , wherein the non-propagating signals are transmitted and received over NFC (near field communication) antennas of the wireless portable radio and the plurality of other wireless portable radios. 
     
     
       12. The wireless portable radio of  claim 11 , wherein the non-propagating signals obey a 1/r 6  propagating law, wherein the non-propagating radio signal power falls off at a rate of about 1/r 6  where r is the distance between the transmitting and receiving NFC antennas. 
     
     
       13. The method of  claim 6 , wherein the non-propagating signals are defined as a signal having a substantially magnetic field component or a substantially electrical field component but not both, which obeys a 1/r 6  propagating law, wherein the non-propagating radio signal power falls off at a rate of about 1/r 6  where r is the distance between transmitting and receiving antennas of the first wireless portable radio and each of the second wireless portable radios. 
     
     
       14. The wireless portable radio of  claim 1 , wherein the wireless portable radio and each of the plurality of other wireless portable radios are within NFC (near field communication) distance of each other. 
     
     
       15. The method of  claim 6 , wherein the first wireless portable radio and each of the plurality of second wireless portable radios is within NFC (near field communication) distance of each other. 
     
     
       16. The apparatus of  claim 1 , wherein the controller is configured to create the traffic encryption key as a function of a user input at the wireless portable radio. 
     
     
       17. The method of  claim 6 , further comprising creating, at the first wireless portable radio, the traffic encryption key as a function of a user input at the first wireless portable radio.